So I just purchased a 2016 optima and on my way home the speedo went from 55 to all the way right then all the way left and would not show the speed of the car anymore. I took the car back to the dealer but they could not replicate the issue. So I went and picked the car back up and it did it again!! So I took the car back to the dealer. Is there a digital speedo? Is it a wiring issue? If I replace the whole unit could it solve the issue?